KR20000021700A - Method for hydrogenation of conjugated diene polymer - Google Patents

Abstract

PURPOSE: Unsaturated double bond of conjugated diene polymer is hydrogenated to high yield by a new catalyst. CONSTITUTION: The unsaturated double bond of conjugated diene polymer and copolymer of the conjugated diene monomer and aromatic vinyl monomer are selectively hydrogenated. The diene polymer and copolymer are prepared by living polymerization using organic alkali metal initiator, and a terminal of the living polymer is inactivated by hydrogenation. Double bond of the obtained polymer is hydrogenated at 0-150°C, 1- 100 kg-f/cm¬2 for 15-1440 minutes by monocyclopentadienyl titanium compound(formula 1; R1 and R2 are same or not, F, Cl, Br and I; R3, R4, R5 and R6 are same or not, C1-C12 alkyl or alkoxy group, C6- C20 aryl, aryloxy or cycloalkyl group; R7 is C2-C4 alkyl, ether group, O or S) and hydrogen.

Description

Hydrogenation of conjugated diene polymer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogenation method of a conjugated diene polymer, and has a high activity in selectively adding hydrogen to an unsaturated double bond of a conjugated diene unit in order to improve durability, oxidation resistance, weather resistance, etc. of a copolymer used as a modifier. The present invention relates to a method of hydrogenating an unsaturated double bond of a conjugated diene unit selectively with a new homogeneous organic titanium catalyst having a high yield of hydrogenation and hydrogenation reproducibility.

Polymers of conjugated diene monomers such as 1,3-butadiene and isoprene or copolymers of conjugated dienes with vinylaromatic monomers such as styrene copolymerizable with these are widely used as elastomers.

These polymers can be vulcanized by having double bonds in the polymer's inner chain, but these structural properties also contribute to deterioration of durability and oxidation resistance.

On the other hand, block copolymers of conjugated dienes and vinyl aromatic monomers used as thermoplastic elastomers can be reused by expressing the corresponding physical properties without undergoing a separate vulcanization process, and are often used as impact-resistant transparent resins or modifiers of polyolefin and polystyrene resins. do.

However, while the double bonds of such polymers work advantageously as mentioned above, they also have extremely contradictory properties that fatally lower the stability of heat resistance, oxidation resistance, weather resistance, etc. of the final material.

Therefore, such a polymer is limited in use because it should be used only in a range not exposed to the outside.

On the other hand, the solution for improving the durability and oxidation resistance by solving such a problem is a method of partially or completely saturated by adding hydrogen to the double bonds in the polymer.

As a method of hydrogenating a polymer having an olefinic double bond has been reported, it can be divided into two broadly.

The first method uses a heterogeneous catalyst, and the second method uses a Ziegler catalyst or a homogeneous catalyst of an organometallic compound such as rhodium or titanium.

Among these, a hydrogenation reaction using a heterogeneous catalyst is a method of dissolving an olefinic polymer in a suitable solvent and then contacting hydrogen in the presence of a heterogeneous catalyst. This method is relatively incompatible due to steric hindrance of the polymer and is relatively low. Due to the high viscosity of the polymer, which is a reactant, there is a problem in that the contact between the reactant and the catalyst is not easy. In addition, the polymer is strongly adsorbed on the catalyst surface and does not fall once hydrogen is added, making it very difficult for other non-hydrogenated polymers to approach the active site. In this case, the complete addition of hydrogen to the double bonds requires a large amount of catalyst and harsh reaction conditions at high temperatures and pressures, often resulting in polymer degradation and gelation. In particular, when the hydrogenation is carried out under such severe reaction conditions, in the case of the copolymer of conjugated diene and vinyl aromatic monomer, double bonds of aromatic monomers are saturated at the same time, so that it is difficult to selectively hydrogenate only the olefinic polymer.

In addition, it is extremely difficult to physically separate the catalyst from the hydrogenated polymer solution, and some heterogeneous catalysts are strongly adsorbed with the polymer, making it impossible to completely remove them.

On the other hand, the hydrogenation reaction using a homogeneous catalyst is higher in activity than in the case of using a heterogeneous catalyst, and the hydrogenation may be performed in a high yield under mild conditions at low temperature and low pressure even with a small amount. In addition, hydrogen can be added only to the double bond of the conjugated diene monomer except the double bond of the aromatic monomer in the copolymer chain of the vinylaromatic monomer and the conjugated diene monomer by appropriately controlling the low-temperature hydrogenation conditions. It can also give a selective hydrogenation function.

Nevertheless, the method of hydrogenating a double bond of a conjugated diene polymer using a homogeneous catalyst has a low stability of the catalyst itself, and it is very difficult to separate the catalyst in the degraded state from the hydrogenated polymer.

On the other hand, several methods for the hydrogenation or selective hydrogenation of unsaturated double bonds of conjugated diene polymers have been reported, for example, US Pat. No. 3,494,942; 3,634,594; 3,670,054; And 3,700,633 and the like include suitable catalysts known in the prior art, in particular Group 8, 9, 10 metals for the hydrogenation or selective hydrogenation of polymers containing ethylenically unsaturated double bonds and polymers having aromatic and ethylenically unsaturated double bonds. A method of using a catalyst or catalyst precursor material containing is described.

The catalyst used in the process described in this patent is prepared by combining a Group 9, 10 metal, in particular a nickel or cobalt compound with a suitable reducing agent such as aluminum alkyl. It is also known in the prior art that aluminum alkyl is the preferred reducing agent, but in addition the Group 1, 2 and 13 metals of the periodic table of the elements, in particular lithium, magnesium and aluminum alkyl or hydrides, are effective reducing agents. At this time, the Group 1, Group 2 and Group 13 metals and Group 8, 9 and 10 metals are combined in a range of 0.1: 1 to 20: 1 molar ratio, preferably 1: 1 to 10: 1 molar ratio.

U.S. Patent 4,501,857 discloses that hydrogenation of conjugated diene polymers in the presence of at least one bis (cyclopentadienyl) titanium compound and at least one hydrocarbon lithium compound enables selective hydrogenation of double bonds in the polymer.

In US Pat. No. 4,980,421, bis (cyclopentadienyl) titanium compounds can be added directly with an appropriate combination ratio of alkoxy lithium compounds, or organic lithium compounds can be added as alcoholic or phenolic compounds or reaction mixtures. It has been found that by using a combination of an alkoxy lithium compound and a bis (cyclopentadienyl) titanium compound, pseudohydrogenation activity can be obtained. The catalyst used herein is said to be active enough to be effective and to not require a deliming step, even when used in small amounts so as not to adversely affect the stability of the hydrogenated polymer.

In US Pat. No. 4,673,714, the bis (cyclopentadienyl) titanium compound preferably hydrogenates a double bond of a conjugated diene, wherein the use of alkyllithium is not required. A specific example of such a titanium compound is a bis (cyclopentadienyl) titanium diaryl compound, which mentions the use of a hydrocarbon lithium compound as an advantage of this catalyst system.

U.S. Pat.No. 5,039,755 also discloses a process for the hydrogenation of conjugated diene polymers comprising polymerizing or copolymerizing conjugated diene monomers with organic alkali metal polymerization initiators in a suitable solvent to produce a living polymer. At this time, the resulting living polymer is terminated by the addition of hydrogen. Selective hydrogenation of the double bond in the conjugated diene unit of the terminated polymer was carried out in the presence of a (C ₅ H ₅ ) ₂ TiR ₂ catalyst, where R is an arylalkyl group.

U.S. Patent No. 5,243,986 discloses that a copolymer of styrene-butadiene-isoprene can be selectively hydrogenated only with a double bond of conjugated diene by using a specific titanocene compound and a reducing agent.

U.S. Pat.No. 5,583,185 discloses Cp ₂ Ti (PhOR) ₂ (where Cp is cyclopentadienyl and OR is an alkoxy compound having 1-4 carbon atoms) or Cp ₂ TiR ₂ ( Provided that R is CH ₂ PPh ₂ ) for the hydrogenation of double bonds of conjugated dienes.

However, such a homogeneous catalyst is generally very sensitive to the external environment and easily deteriorates when there is air or moisture, and there is a problem that the hydrogenation activity is greatly changed depending on the reduction state of the catalyst. As a result, since the reproducibility of the hydrogenation reaction is poor, it is difficult to obtain a hydrogenated polymer that satisfies both high hydrogenation rate and high reproducibility at the same time.

In addition, the catalytically active species tends to change into an inert material as the reaction proceeds, which in turn causes the hydrogenation activity to decrease, thereby reducing the reproducibility of the reaction. This tendency causes serious obstacles to polymer hydrogenation reactions aimed at improving the durability and oxidation resistance of polymers. In addition, in the homogeneous catalyst, the hydrogenation rate is greatly influenced by the stability of the catalyst during the hydrogenation reaction.

Therefore, the industrial application of the hydrogenation reaction process of the polymer by a homogeneous catalyst has the above problems, and there is a strong demand for the development of a stable and reproducible high activity hydrogenation catalyst that can solve these problems.

An object of the present invention is to solve the problem of hydrogenating unsaturated double bonds of conjugated diene polymers using the homogeneous catalyst as described above, while avoiding the problems caused by the general homogeneous hydrogenation catalyst and at the same time high hydrogenation rate and high It is to provide a hydrogenation method using a new catalyst capable of producing a hydrogenated polymer with reproducibility.

The hydrogenation method of the conjugated diene polymer of the present invention for achieving the above object is to selectively hydrogenate only the double bond of the conjugated diene in the polymer selected from the homopolymer of the conjugated diene monomer and the copolymer of the conjugated diene monomer and an aromatic vinyl monomer. 1) preparing a living polymer by copolymerizing at least one conjugated diene monomer with a homopolymer or vinylaromatic monomer using an organic alkali metal as an initiator; 2) hydrogenating the living polymer to deactivate the terminal; And 3) adding a monocyclopentadienyl titanium compound represented by the following Chemical Formula 1 together with hydrogen to the terminated polymer to selectively hydrogenate the unsaturated double bond.

Formula 1

Wherein R ₁ and R ₂ are the same as or different from each other, and are selected from halogen atoms such as fluorine, chlorine, bromine or iodine group,

R ₃ to R ₆ are the same as or different from each other, and are selected from a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group, an aryl group having 6 to 20 carbon atoms, an aryloxy group or a cycloalkyl group,

R ₇ is selected from an alkyl or ether group having 2 to 4 carbon atoms, an oxygen atom or a sulfur atom.

The present invention will be described in more detail as follows.

The catalyst represented by the formula (1) used in the hydrogenation reaction of the present invention is obtained by reacting a monocyclopentadienyl titanium compound by mixing with an organic alkali metal in a suitable solvent.

When this type of catalyst is used to hydrogenate an unsaturated double bond of a conjugated diene polymer, it is possible to maximize the contact between the catalyst species and the polymer by imparting a suitable steric hindrance to the catalyst species itself, thereby enhancing the miscibility with the polymer solution. have.

In addition, by reducing the association between the catalyst species itself to maintain the life of the catalyst species it is possible to perform the hydrogenation under milder conditions.

In addition, when the unsaturated double bond of the conjugated diene polymer is hydrogenated using the monocyclopentadienyl titanium compound catalyst in the oligomeric state according to the present invention, the catalytic activity is excellent, and hydrogenation can be performed under mild conditions. In the copolymer of a compound with a vinyl-substituted aromatic hydrocarbon, the unsaturated double bond of the conjugated diene unit can be extremely selectively hydrogenated.

Specific examples of the catalyst represented by Chemical Formula 1, which play such a role are as follows; 4,4'-butylidene-bis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium fluoride), 4,4'-butylidene- (bis (6-t- Butyl-3-methylphenoxy) monocyclopentadienyltitanium chloride), 4,4'-butylidene-bis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium bromide), 4,4'-butylidene-bis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium iodide), 4,4'-thiobis ((6-t-butyl- 3-methylphenoxy) monocyclopentadienyltitanium fluoride), 4,4'-thiobis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium chloride), 4,4 ' -Thiobis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium bromide) and 4,4'-thiobis ((6-t-butyl-3-methylphenoxy) monocyclopenta Dienyltitanium iodide), which may be used alone or in combination.

The amount of the hydrogenation catalyst used is preferably 0.01 to 20 mmol based on the mole of titanium metal per 100 g of polymer, and more preferably 0.05 to 2 mmol based on the mole of titanium metal per 100 g of polymer.

Hydrogen may be added to the unsaturated double bond of the copolymer of a conjugated diene polymer having a molecular weight of 500 to 1,000,000 or a vinyl-substituted aromatic monomer copolymerizable with a conjugated diene and a random or block copolymer conjugated diene unit using the above hydrogenation catalyst. have.

For hydrogenation, first, a polymer must be prepared to obtain a living polymer.

As is well known, polymers containing ethylenically unsaturated double bonds and any aromatic unsaturated double bonds can be prepared by homopolymerizing one or more polyolefins, in particular diolefins, or by copolymerizing with one or more alkenyl aromatic hydrocarbon monomers.

The copolymer can be linear, constellation or radial as well as random, tapered, block or combinations thereof.

Ethylenic unsaturated double bonds alone, or copolymers containing both aromatic and ethylenically unsaturated double bonds can be prepared using anionic initiators or polymerization catalysts, such as organolithium compounds. In the preparation of the polymers, the process may employ conventional methods, ie bulk, solution or emulsion techniques.

In this case, n-butyllithium or s-butyllithium may be used as the organolithium compound.

Here, the conjugated diene-based compound which can be polymerized into an anion type is 1,3-butadiene, isoprene, piperylene, phenylbutadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1, A conjugated diene compound containing 4 to 12 carbon atoms such as 3-octadiene can be used, and preferably a conjugated diolefin having 4 to 9 carbon atoms is used.

The vinyl aromatic hydrocarbon copolymerizable with the conjugated diene compound may include styrene, styrene substituted with various alkyl groups, styrene substituted with alkoxy groups, 2-vinyl pyridine, 4-vinyl pyridine, vinyl naphthalene, vinyl naphthalene substituted with alkyl groups, and the like. Such vinyl aryl compounds.

The hydrogenation reaction of the present invention is carried out using a polymer obtained by polymerizing conjugated diene in an inert solvent.

Here, an inert solvent means a solvent which does not react with any reactants of polymerization or hydrogenation reaction, and suitable solvents include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane and n-octane; Aliphatic ring hydrocarbons such as cyclohexane and cycloheptane; And ethers, such as diethyl ether and tetrahydrofuran, These can be selected and can be used individually or in mixture.

In addition, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene can also be used within the range where hydrogen is not added to the aromatic double bond under selected hydrogenation reaction conditions.

The hydrogenation reaction of the present invention is carried out at a concentration of 1 to 50% by weight, preferably 5 to 25% by weight of the polymer relative to the solvent.

When the polymerization is completed as described above, the next step, the terminal anion is inactivated by stirring the polymer solution existing in the living state at a temperature range of room temperature to 80 ° C. at a hydrogen pressure of 5 atmospheres for several minutes to 360 minutes. At this time, the deactivation completion point of the terminal anion is determined as the time point at which the vermiculite, the intrinsic color of the living polymer, turns to colorless, and is confirmed by visual or ultraviolet spectroscopy.

The method of inactivating the terminal of a living state polymer is to stir for several minutes to 360 minutes by the hydrogen pressure of 5 kg * f / cm <2> at the temperature of normal temperature -80 degreeC, Preferably it is suitable to stir for 30 to 90 minutes.

Finally, after maintaining the end-treated solution at a constant temperature under hydrogen or an inert gas atmosphere, by adding a hydrogenation catalyst represented by the formula (1) in a stirred or unstirred state, and then injecting hydrogen gas at a constant pressure The hydrogenation reaction is complete.

At this time, the inert gas is helium, nitrogen, argon, etc., which means a gas that does not react with any reactants of the hydrogenation reaction, air or oxygen is not preferable because the oxidation or decomposition of the hydrogenation catalyst to cause the catalyst deactivation.

The hydrogenation reaction is generally carried out in the temperature range of 0 to 150 ℃. If the temperature is lower than 0 ° C., the activity of the catalyst decreases and the rate of hydrogen addition decreases, requiring a large amount of catalyst, which is not economical, and the polymer is easily precipitated by insolubilization of the hydrogenated polymer. On the other hand, when the reaction temperature is higher than 150 ° C., it is easy to cause the polymer species to decompose and decompose, causing gelation or decomposition of the polymer, and also to easily hydrogenate the aromatic double bond, which tends to lower the selectivity of hydrogenation. In view of such a point, the reaction temperature is more preferably in the range of 50 to 140 ° C.

In addition, although the pressure of hydrogen used for a hydrogenation reaction is not specifically limited, 1-100 kg * f / cm <2> is suitable. If the pressure of hydrogen is less than 1 kg · f / cm 2, the hydrogenation rate is slow, and at pressures exceeding 100 kg · f / cm 2, gelation, which is a substantially unnecessary side reaction, is caused. More preferably, the hydrogen pressure is 2 to 30 kg · f / cm 2, and the optimum hydrogen pressure is selected in relation to the hydrogenation conditions such as the addition amount of the catalyst. When the amount of the hydrogenation catalyst is substantially small, the hydrogen pressure is preferably high pressure.

The hydrogenation reaction time of the present invention is usually from minutes to 1440 minutes. More preferably, 30 minutes-360 minutes are suitable. In the selection of other hydrogenation reaction conditions, the hydrogenation reaction time is appropriately selected within the above range and carried out. The hydrogenation reaction of this invention may use any method, such as a batch type and a continuous type.

On the other hand, the progress of the hydrogenation reaction can be understood to track the hydrogen uptake amount.

When hydrogenating using the catalyst of the present invention, it is possible to obtain a polymer in which the unsaturated double bond of the conjugated diene unit of the polymer is at least 50%, preferably at least 90%. More preferably, when hydrogenating a copolymer of a conjugated diene and a vinyl aromatic hydrocarbon, the hydrogenation rate of the unsaturated double bond of the conjugated diene unit is 90% or more, and the hydrogenation rate of the aromatic double bond is less than 5%. It is possible to obtain a copolymer in which a double bond is selectively hydrogenated.

As described above, when the conjugated diene polymer is hydrogenated using a high activity new catalyst, hydrogenation can be carried out under mild conditions, and in particular, unsaturated double bonds of conjugated diene units in the copolymer of conjugated diene and vinyl aromatic hydrocarbons. Can be hydrogenated extremely selectively. In addition, since the raw material used for the hydrogenation using the catalyst of the present invention is a conjugated diene polymer, it is possible to continuously hydrogenate in the same reactor, and at the same time, it can exhibit extremely high activity even with the addition of a small amount of catalyst. It is advantageous to apply.

Hereinafter, the present invention will be described in detail with reference to the following Examples, but the present invention is not limited thereto.

Preparation Example 1 Synthesis of 4,4′-Butylidene-bis ((6-t-butyl-3-methylphenoxy) CpTiCl ₂ ) Catalyst

In a 200 ml Schlenk reactor, 4.4 g of monocyclopentadienyl titanium trichloride (CpTiCl ₃ ) was dissolved in 100 ml of toluene under an inert gas atmosphere, followed by 4,4'-butylidene-bis ( 10 mmol of 4,4'-butylidene-bis (6-t-butyl-3-methylphenoxy) lithium obtained by reacting 6-t-butyl-3-methylphenol) with n-butyllithium was added slowly, Stir at room temperature for 1 hour. After 1 hour, a part of the mixture was taken and the reaction result was confirmed by using an NMR analyzer.

Yield: 91%

¹ H-NMR (CDCl ₃ ) δ (ppm): 7.049 (ArH, 2H, s), 6.401 (ArH, 2H, s), 6.673 (C ₅ H ₅ , 10H, s)

4.011 (CH, 1H, t), 2.117 (CH ₃ , 6H, s),

1.331 (C (CH ₃ ) ₃ ; CH (CH ₂ ) ₂ , 22H, s), 0.971 (CH ₃ , 3H, t)

Preparation Example 2 4,4′-thiobis ((6-t-butyl-3-methylphenoxy) CpTiCl ₂ ) Catalyst Synthesis

After dissolving 4.4 g of monocyclopentadienyl titanium trichloride (CpTiCl ₃ ) in 100 ml of toluene in an inert gas atmosphere in a 200 ml Schlenk reactor, 4,4'-thiobis (6-t) was dissolved. 10 mmol of 4,4'-thiobis (6-t-butyl-3-methylphenoxy) lithium obtained by reacting n-butyllithium) with n-butyllithium was slowly added, followed by stirring at room temperature for 1 hour. It was. After 1 hour, a part of the mixture was taken and the reaction result was confirmed by using an NMR analyzer.

Yield: 92%

¹ H-NMR (CDCl ₃ ) δ (ppm): 6.987 (ArH, 2H, s), 6.493 (ArH, 2H, s), 6.673 (C ₅ H ₅ , 10H, s)

2.295 (CH ₃ , 6H, s), 1.217 (C (CH ₃ ) ₃ , 18H, s)

Preparation Example 3 Synthesis of Styrene-Butadiene-Styrene Block Copolymer

4800 g of cyclohexane was added to a 10-liter autoclave reactor, 11 g of tetrahydrofuran, 124 g of styrene monomer, and 16 mmol of n-butyllithium were injected, followed by polymerization for 30 minutes. Then, 552 g of 1,3-butadiene monomer was injected into the reactor for 1 hour. Polymerized. Finally, 124 g of styrene monomer was added and polymerized for 30 minutes, and then the living polymer solution was stirred at 60 ° C. at a hydrogen pressure of 60 atm for 60 minutes to inactivate terminal anions.

As a result, a styrene-butadiene-styrene block copolymer having a bound styrene content of 31.0% (block styrene content 30.0%), a 1,2-vinyl bond content of butadiene units (38.5% (26.6% in total polymer), and a number average molecular weight of about 50,000) Got.

Preparation Example 4 Synthesis of Styrene-Butadiene Random Copolymer

In a 10-liter autoclave reactor, 6000 g of cyclohexane was added, 100 g of tetrahydrofuran, 130 g of styrene monomer, and 870 g of butadiene monomer were added, followed by polymerization for 1 hour by addition of 10 mmol of n-butyllithium, followed by a living polymer solution at 60 ° C. The terminal anions were inactivated by stirring at 5 atmospheres of hydrogen for 60 minutes.

As a result, a styrene-butadiene random copolymer having a binding styrene content of 13%, a 1,2-vinyl bond content of butadiene units of 57%, and a number average molecular weight of about 100,000 was obtained.

Preparation Example 5 Synthesis of Butadiene Homopolymer

In a 10-liter autoclave reactor, 6000 g of cyclohexane was added, 1000 g of butadiene monomer was added, and 10 mmol of n-butyllithium was added to polymerize for 2 hours. The living polymer solution was then heated at 60 ° C. under a pressure of 5 atm for 60 minutes. Stirring deactivated the terminal anion.

As a result, a butadiene homopolymer having a 1,2-vinyl bond content of butadiene units of 10%, a cis bond content of 35%, and a number average molecular weight of about 100,000 was obtained.

Preparation Example 6 Synthesis of Isoprene Homopolymer

In a 10-liter autoclave reactor, 6000g of cyclohexane was added, 1000g of isoprene monomers were added, and 20mmol of n-butyllithium was added to polymerize for 2 hours.The living polymer solution was then heated at 60 ° C. under a pressure of 5 atm for 60 minutes. Stirring deactivated the terminal anion.

As a result, an isoprene homopolymer having a 1,2-vinyl bond content of 10% of isoprene units and a number average molecular weight of about 50,000 was obtained.

Examples 1-3

2800 g of the solution, each containing 400 g of the polymer obtained according to Production Examples 3 to 5 above, was placed in a 5 L autoclave reactor and heated to 60 ° C. at 400 rpm (rpm). Then, 1.6 mmol of the catalyst prepared according to Preparation Example 1 was added to the polymer solution, and then the reactor was pressurized with 10 kg · f / cm 2 of hydrogen to carry out a hydrogenation reaction for 180 minutes. After the reaction was completed, the reactor was cooled down, the pressure was reduced to normal pressure, and the reaction solution was added to methanol to precipitate the polymer.

The hydrogenation rate of butadiene units and hydrogenation rate of styrene units in the final hydrogenation rate of the obtained hydrogenated polymer was confirmed by ¹ H-NMR analysis, the results are shown in Table 1 below.

Example One 2 3 Polymer (Production Example) 3 4 5 % Of hydrogenation in butadiene units 97 98 96 Hydrogenation rate in styrene units (%) Less than 1 Less than 1 Less than 1

Examples 4-6

The hydrogenation reaction was carried out in the same manner as in Example 1, except that the polymers obtained according to Preparation Examples 3 to 5 were used, respectively, and the compounds obtained in Preparation Example 2 were used as catalysts. The results are shown in Table 2 below.

Example 4 5 6 Catalyst (Production Example) 2 Polymer (Production Example) 3 4 5 % Of hydrogenation in butadiene units 97 97 95 Hydrogenation rate in styrene units (%) Less than 1 Less than 1 Less than 1

Examples 7-8

The hydrogenation reaction was carried out in the same manner as in Example 1, except that the polymer obtained according to Preparation Example 6 was used, and the compound obtained according to Preparation Examples 1 and 2 was used as a catalyst. The results are shown in Table 3 below.

Example 7 8 Catalyst (Production Example) One 2 Hydrogenation rate in isoprene units (%) 95 95 Less than 1 Hydrogenation rate in styrene units (%) Less than 1

When the conjugated diene polymer is hydrogenated using the catalyst according to the present invention from the results of Tables 1 to 3, the catalytic activity is excellent, and hydrogenation is possible under mild conditions. Particularly, the conjugated diene compound and the vinyl substituted aromatic hydrocarbon It can be seen that in the copolymer, only unsaturated double bonds of conjugated diene units are hydrogenated extremely selectively.

As described in detail above, in the case of hydrogenating an unsaturated double bond of a conjugated diene polymer using a monocyclopentadienyltitanium compound catalyst according to the present invention, it is miscible with the polymer solution by imparting appropriate steric hindrance to the catalyst species itself. To maximize contact between the catalytic species and the polymer; By reducing the association between the catalytic species itself, not only the life of the catalytic species can be maintained and hydrogenation can be carried out under milder conditions; In a copolymer of a conjugated diene-based compound with a vinyl-substituted aromatic hydrocarbon, the unsaturated double bond of the conjugated diene unit can be extremely selectively hydrogenated; Since the conjugated diene polymer is used as a raw material, it is possible to continuously hydrogenate in the same reactor, and at the same time, since it is an economical and simple process that can exhibit extremely high activity by adding a small amount of catalyst, it can be particularly useful industrially.

Claims (11)

In the selective hydrogenation of only the double bond of the conjugated diene in a polymer selected from homopolymers of conjugated diene monomers and copolymers of conjugated diene monomers and aromatic vinyl monomers, 1) preparing a living polymer by copolymerizing at least one conjugated diene monomer with a homopolymerized or vinylaromatic monomer using an organic alkali metal as an initiator; 2) hydrogenating the living polymer to deactivate the terminal; And 3) A hydrogenation method of a conjugated diene polymer, characterized in that the step of adding a monocyclopentadienyl titanium compound represented by the following formula (1) with hydrogen to the end-treated polymer to selectively hydrogenate the unsaturated double bond. Formula 1 Wherein R ₁ and R ₂ are the same as or different from each other, and are selected from halogen atoms such as fluorine, chlorine, bromine or iodine group, R ₃ to R ₆ are the same as or different from each other, and are selected from a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group, an aryl group having 6 to 20 carbon atoms, an aryloxy group or a cycloalkyl group, R ₇ is selected from an alkyl or ether group having 2 to 4 carbon atoms, an oxygen atom or a sulfur atom. The method of claim 1, wherein the hydrogenation of the unsaturated double bond is carried out under the conditions of reaction temperature 0 ℃ to 150 ℃, reaction pressure 1 ~ 100kg · f / cm ² , catalyst amount 0.01 ~ 20mmole / 100g polymer, reaction time 15 ~ 1440 minutes A hydrogenation method of a conjugated diene polymer characterized by the above-mentioned. The hydrogenation of an unsaturated double bond according to claim 1 or 2, wherein the hydrogenation of the unsaturated double bond is carried out at a reaction temperature of 50 ° C. to 140 ° C., a reaction pressure of 5 to 20 kg · f / cm ² , a catalyst amount of 0.05 to ² mmole / 100 g polymer, and a reaction time of 30 to 360 minutes. Process for the hydrogenation of conjugated diene polymer, characterized in that carried out in. According to claim 1, wherein the compound represented by the formula (1) is 4,4'- butylidene-bis ((6-t- butyl-3- methylphenoxy) monocyclopentadienyl titanium fluoride), 4, 4'-butylidene- (bis (6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium chloride), 4,4'-butylidene-bis ((6-t-butyl-3 -Methylphenoxy) monocyclopentadienyltitanium bromide), 4,4'-butylidene-bis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium iodide), 4 , 4'-thiobis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium fluoride), 4,4'-thiobis ((6-t-butyl-3-methylphenoxy ) Monocyclopentadienyltitanium chloride), 4,4'-thiobis ((6-t-butyl-3-methylphenoxy) monocyclopentadienyltitanium bromide) and 4,4'-thiobis ((6 -t-butyl-3-methylphenoxy) monocyclopentadienyltitanium iodide) Hydrogenation of the conjugated diene polymer to that feature. The method of hydrogenating a conjugated diene polymer according to claim 1, wherein an organolithium compound is used as the organoalkali metal initiator. 6. The method for hydrogenating a conjugated diene polymer according to claim 5, wherein the organolithium compound uses n-butyllithium or s-butyllithium. The method for hydrogenating conjugated diene polymers according to claim 1, wherein isoprene or butadiene is used as the conjugated diene monomer. The method of hydrogenating a conjugated diene polymer according to claim 1, wherein styrene or alphamethyl styrene is used as the aromatic vinyl monomer. The method for hydrogenating a conjugated diene polymer according to claim 1, wherein the amount of the aromatic vinyl monomer to the conjugated diene monomer is 0 to 9 by weight. The hydrogenation method of the conjugated diene polymer according to claim 1, wherein the homopolymer of the conjugated diene monomer or the copolymer of the conjugated diene monomer and the aromatic vinyl monomer is used having a number average molecular weight of 500 to 1,000,000. The method of claim 1, wherein the hydrogenation is carried out such that at least 90% of the conjugated diene double bond is hydrogenated, and less than 1% of the double bond of aromatic vinyl is hydrogenated.